Hornsby is a tiny lunar crater in the western part of the Mare Serenitatis, a lunar mare in the northeast quadrant of the Moon's near side. It is a solitary formation that is located at least 100 kilometers from any significant craters, although the small Krishna crater lies about 50 km to the west-northwest. To the north-northwest is the Linné crater, a feature notable for its skirt of high albedo material.